Profile

Cover photo
Thad Szabo
Attended University of Pennsylvania
8,553 followers|508,102 views
AboutPostsPhotosVideos

Stream

Thad Szabo

Shared publicly  - 
 
I may not have enough musicians in my circles here on G+.

The news about the failed SpaceX launch was all over my feed. That could not have been a good way for Elon Musk to spend his birthday. However, it gives him (and SpaceX) something to investigate and get better at. It wasn't an optimal present, but it's a challenge - a present in disguise?

The news that was not on my feed was the passing of Chris Squire, the bassist for Yes. I got to see Yes on the Union tour back in 1991 thanks to friends with tickets. It was a concert that has shaped my musical tastes ever since. "Awaken" was on the set list for both shows I attended, with Squire wielding his triple-neck bass. Unbelievable musicianship, all around.

If you have about 16 minutes, find a recording of "Awaken" to listen to. If you only have about 10 minutes, listen to "Heart of the Sunrise." Do so, and focus on the bass lines. And don't ever let his music slip away.
7
Stephen Rahn's profile photo
 
Musician here. I played a lot of bass when I was younger and Squire was always one of my idols. One of the most innovative musicians I have ever had the pleasure to hear.
Add a comment...

Thad Szabo

Deep sky imaging  - 
 
Here's the γ Cyg mosaic that I've been slowly shooting over a few years. There's 24 panels in this mosaic.
The Milky Way runs thick and bright through the constellation Cygnus. For observers in mid-northern latitudes, this portion of the sky passes high… - Thad Szabo - Google+
18
4
Ahmed Eid's profile photoB.G.Sebastian Loewen L.'s profile photoASTROSELFIE's profile photoUniverseSpace BioC's profile photo
 
That's an amazing amount of work and effort +Thad Szabo 
Add a comment...

Thad Szabo

Solar system imaging  - 
 
Saturn is not well placed for me this year (or for the next 5 or 6 years, to be honest), so let me go through the process it took to get this.

Equipment:
Celestron Edge HD 9.25" on CGEM
3x Barlow
Point Grey Flea 3 color camera

I went to a talk by Christopher Go last summer who cautioned against recording longer than the rotation of an object would take to blur features. His advice was to derotate and stack individual processed frames in WinJUPOS. Thus, no AVI used to make this was longer than 60 seconds. I was shooting at 11fps for 600 frames. I was able to do so for about an hour.

I did an initial stacking with one alignment point in AutoStakkert to find the highest quality AVIs. There were 30 that made the cut. I noticed a weird artifact that appeared in the rings if I tried to stack too many frames. I've seen this happen before with Saturn. It's as if a resonance develops in the seeing that creates false features. I had to stack only the best 45 frames from each AVI to avoid having it appear.

I tried various ways to automate processing the stacks, but no simple solution presented itself in either GIMP or PS. I went to PixInsight, and setup actions to crop, rescale, multiscale linear transform, rotate, and align channels. This was easy enough to repeat (I still have to learn scripting in PI), and I had 30 frames to derotate and combine in WinJUPOS. I really like the wavelet option in PixInsight. I feel like it gives far more control than Registax or other stacking software, and it's easy to preview before you let it rip.

The final image from WinJUPOS underwent another quick touch up in PI before adding final info in PS CS 5.1. No, there's still no Encke's Division, but for a planet less than 35° off the horizon, I'll take it.
30
2
Tanmay Chowhan's profile photoThad Szabo's profile photoASTROSELFIE's profile photoUniverseSpace BioC's profile photo
4 comments
 
One of the key points of data acquisition is to generate a high signal-to-noise ratio. Stretching intensities in the final image, rather than getting data that does a good job of maxing out pixel range, will give a low signal-to-noise ratio. Better to find the combination of magnification, frame rate, and exposure time which limits your susceptibility to bad seeing while pushing the highest pixels close to maximum intensity. I keep an eye on the histogram in FlyCapture when I'm shooting to make sure that equatorial belt (the brightest feature in the image) stays near 100% when recording. You can't introduce these pixels later on, and you risk having a "flat" image by using too high a magnification and/or frame rate.

Additionally, the drizzle option in AutoStakkert gives weird results at the edges of alignment points if the histogram isn't pushed to 80% while recording over most of the image. You may argue that you don't need drizzle if you stack Barlows, but with fewer photons per pixel, the high magnification method gives less data to begin with.
Add a comment...

Thad Szabo

Shared publicly  - 
 
We had a night of amazing seeing during one of my labs earlier this semester. I was able to capture many videos of Jupiter with the 14" Schmidt-Cassegrain and a 2x Barlow and Point Grey Flea3 color camera at +Cerritos College.

During later meetings, I had students from my Tuesday and Wednesday astronomy labs run the videos through AutoStakkert2 and process the stacks that were produced with GIMP to enhance the detail. I then took the best of their processed images and derotated them with WinJUPOS to produce this.

Thank you to all my students in those labs! Your work helped to produce this image of Jupiter with the shadow of Callisto on its atmosphere. 
39
3
Gary Ray R's profile photoDominic Savarese's profile photoThomas Phillips's profile photoASTROSELFIE's profile photo
2 comments
 
Great shot and your students learned skills I wish I had. 
+Ted Ewen, you might be interested.
Add a comment...

Thad Szabo

Shared publicly  - 
 
This sounds like Bear McCreary met up with an early 90s industrial band. That is a good thing, and hard to believe this is all possible with one instrument.

At some point, I have to understand that I'm not going to be able to play all the instruments, or speak all the languages, or do all the math and science, and just enjoy performances like this.
On a list of things I most anticipated sitting down to cover on Colossal today, the hurdy gurdy probably wasn't in the top thousand topics, but then I stumbled onto this video and had to share it. The piece is called Omen, written and performed by Guilhem Desq, who uses an electrified version
12
18
Sam Ballowe's profile photoDean Lovett's profile photoWilliam “TazWarner” Bidinger's profile photoJanek H's profile photo
4 comments
 
wow super!
Add a comment...

Thad Szabo

Shared publicly  - 
 
It's always fun to learn how to generate new sequences and learn their properties! Also, as my wife pointed out, this would make a cool tiling to do on a wall.
 
The plastic number

The sequence of side lengths of equilateral triangles in this picture form the Padovan sequence (1,1,1,2,2,3,4,5,7,9...). Just as the Fibonacci sequence is governed by the properties of the golden ratio, the Padovan sequence is governed by the properties of the so-called plastic number.

The Padovan sequence P(n) is sequence is defined by setting P(1)=P(2)=P(3)=1, and then requiring P(n) = P(n–2) + P(n–3) for n > 3. The generating function for the sequence is given by G(x)=(1+x)/(1–x^2–x^3), which means that if this ratio of polynomials is expanded as a power series in x, the coefficient in G(x) of x^n (i.e., x to the nth power) is equal to P(n). 

The denominator in the formula for the generating function, 1–x^2–x^3, can be regarded as an algebraic encoding of the recurrence relation P(n)–P(n–2)–P(n–3)=0. An easy calculation involving polynomials shows that the product (1–x^2–x^3)(1–x+x^2) is given by 1–x–x^5. This means that the generating function G(x) can be rewritten so that the denominator polynomial is given by 1–x–x^5, which in turn means that, if n is large enough, the sequence will satisfy the recurrence relation P(n) = P(n–1) + P(n–5). 

The picture is an illustration of this last relation. Notice that the big triangle with side 16 is bounded on one side by the preceding triangle in the sequence (of side 12) and the triangle five places earlier in the sequence (of side 4). This corresponds to the fact that P(n) = P(n–1) + P(n–5) for n=12 and P(n)=16.

It turns out that the polynomial 1–x^2–x^3 has exactly one real root, and the plastic number is the reciprocal of this root. Another way to say this is that the plastic number is the unique real solution of the equation x^3=x+1. It is not hard to show using abstract algebra that this solution is an irrational number; the same is true for the golden ratio, which is the larger real solution of the equation x^2=x+1. The decimal expansion of the plastic number is therefore non-recurring; the first few digits are 1.324717957..., and over 10,000,000,000 digits have been computed. 

The plastic number is mathematically significant because it is the smallest Pisot number. A Pisot number is a real root of a monic integer polynomial whose other roots are complex numbers of absolute value less than 1. The word monic means that the highest power of x occurring has a coefficient of 1. The connection with the Padovan sequence is that the ratio P(n+1)/P(n), as n becomes large, tends to the plastic number. (In the case of the Fibonacci numbers, the corresponding ratio approaches the golden ratio.)

The Padovan sequence was described by Richard Padovan in a 1994 essay about the Dutch architect Hans van der Laan. Padovan attributed the discovery of the sequence to van der Laan, so van der Laan sequence would have been a more historically accurate name. The reason for the name plastic is too weak to explain convincingly, but it is intended to convey the sense of something that can be given a three-dimensional shape.

The Padovan sequence has several fairly natural interpretations. One of these is that P(n) is the number of ways of writing n+1 as an ordered sum in which each term is either 2 or 3. For example, P(7) is 4, and this corresponds to the four ways in which 7+1=8 can be written as an ordered sum of 2s and 3s: 8 = 2+2+2+2 = 3+3+2 = 3+2+3 = 3+3+2.

Relevant links

Wikipedia on the plastic number: http://en.wikipedia.org/wiki/Plastic_number

Wikipedia on Pisot numbers, also known as Pisot–Vijayaraghavan numbers or PV numbers: http://en.wikipedia.org/wiki/Pisot–Vijayaraghavan_number

Wikipedia on the Padovan sequence, where this picture comes from: http://en.wikipedia.org/wiki/Padovan_sequence

The Padovan sequence at the On-Line Encyclopedia of Integer Sequences: http://oeis.org/A000931 
(Note that the encyclopedia version contains some additional terms at the beginning relative to the definition of the sequence used here.)

Irrelevant link
I now have the 1969 song Plastic Man by the Kinks (http://goo.gl/6dcpbO) stuck in my head. The BBC refused to play the song when it came out because it contains the word “bum”.

(Picture found via Shecky R and Cliff Pickover on Twitter.)

#mathematics #scienceeveryday  
7
Add a comment...
Have him in circles
8,553 people
Amanda Cole's profile photo
wilfred Densingh A's profile photo
Manuel Valcarcel's profile photo
Frank Merchant's profile photo
Martijn Roelandse's profile photo
‫سعيد سهرابي‬‎'s profile photo
John Bubb's profile photo
Thiago Viana Camata's profile photo
Andreas Pcensored's profile photo

Thad Szabo
moderator

Amateur Astrophotography  - 
 
I compiled the images for this mosaic of the region around Sadr (γ Cygni) during the summers of 2012, 2013, and 2015. It is composed of 24 separate panels. Here's the current "final" version. I might add more later this summer. Or next year. Or the year after that. As long as nothing goes supernova, I can keep adding year after year...
The Milky Way runs thick and bright through the constellation Cygnus. For observers in mid-northern latitudes, this portion of the sky passes high… - Thad Szabo - Google+
19
4
Cheri Payne's profile photoASTROSELFIE's profile photo
Add a comment...

Thad Szabo

Shared publicly  - 
 
The Milky Way runs thick and bright through the constellation Cygnus. For observers in mid-northern latitudes, this portion of the sky passes high overhead in summer. The bright star in this picture is Sadr, or γ Cyg, a supergiant star that will end its life as a supernova. It marks the body of Cygnus the Swan, or the center of the Northern Cross. 

This is a mosaic of 24 separate panels, shot over 8 nights in the summers of 2012, 2013, and 2015. One useful feature of deep sky objects is that - unless there is a supernova - there are not noticeable changes over the span of human lifetimes. I can continue to add to and expand this mosaic throughout my life. 

Deep sky objects visible include open star clusters M29 and NGC 6910, emission nebula IC 1318, dark nebula Barnard 343, and the Crescent Nebula (NGC 6888) in the lower right. The Crescent is particularly interesting, as it was created from the outer layers of a very massive star whose helium core is now exposed as it undergoes fusion and has a surface temperature in excess of 40,000K - a Wolf-Rayet star. This mosaic covers a region of sky 3° 23' wide by 3° 8' high - it would take 42 full moons to cover the entire picture.
This mosaic is a composite of 24 individual panels. Each panel is a stack of between 8 and 16 images shot as 245s exposures with a Celestron Edge HD 9.25" telescope at f/2.3 with HyperStar and Atik 314L+ color CCD camera. The images are pre-processed and stacked in Nebulosity. Each stack is then color calibrated and deconvolved in PixInsight. Microsoft ICE is used to make the mosaic. The mosaic then undergoes some cleanup in PixInsight, and final...
9
Russell Bateman's profile photoThad Szabo's profile photoStephen Rahn's profile photo
4 comments
 
+Thad Szabo My problem is that I am ridiculously obsessed with too many portions of the sky!
Add a comment...

Thad Szabo

Shared publicly  - 
 
This set of videos might be just what my summer needed. I've watched the first one, and I very much like the approach. The list of topics includes some things I've wanted to learn for a long time. A long time...
 
Bill Shillito presents an EXCELLENT lecture series on various topics in higher mathematics. Including logic, set theory, number theory, analysis, topology, & abstract algebra. He even delves into the basics of proof-writing. I recommend this series for EVERYONE, as it shows the many reasons why "math is fun." You know, the reasons they don't show you in high school.
1 comment on original post
4
Add a comment...

Thad Szabo

Shared publicly  - 
 
Back in March, I went to Death Valley with some members of the Astronomy Club from Cerritos College. We had 2 nights of really terrific skies, and I was able to shoot many galaxies. The entire collection of photos is on my flickr account (https://www.flickr.com/photos/astrothad/), but here's the shot I consider the best of the lot. 

This is NGC 4565, The Needle Galaxy. It's an edge-on spiral in Coma Berenices, a region of the sky rich with galaxies. As we move into June and July, the Milky Way will dominate the night sky (especially for the Southern Hemisphere). At the time of year this was shot, the Milky Way rings the the horizon for most of the mid-northern latitudes. This means our view into space is unobstructed by dust and other intervening material in the galaxy. Coma Berenices contains the North Galactic Pole. If you look at the rotation of the Milky Way, the axis points in the direction of this constellation. Since our galaxy would appear like this one if viewed edge-on from the outside, this means we can observe deepest into space when we are looking through the thinnest part.
25
Peter Vogel's profile photoJames Haney's profile photoMichael Jobin's profile photoSandy Nuñez (Sandiasan)'s profile photo
4 comments
 
Amazing..
Add a comment...

Thad Szabo

Shared publicly  - 
 
Here's what Jupiter does in about an hour. I had clouds move in part way through this, so I have more sporadic frames stretching for another 90 minutes or so. This is from 0400 to 0500 UT on 2015-03-14. All frames shot with a Point Grey Flea 3 and Celestron Edge HD 9.25" scope at f/10. Stacking in Autostakkert and final processing in GIMP. 

That brightest dot heading away from Jupiter? That's Ganymede - the largest moon in the solar system. It's the only one that has its own magnetic field, and as such it also has aurorae. The Hubble Space Telescope observed these aurorae recently, and their small fluctuations make a good case for an enormous ocean of salty water under Ganymede's surface.
64
2
Tanmay Chowhan's profile photoKevin Franklin's profile photoThe Rolnick Observatory's profile photoASTROSELFIE's profile photo
12 comments
 
Was just saying, in case you'd tried it too. 
Add a comment...

Thad Szabo

Shared publicly  - 
 
Heads up to all planetary photographers (like +Michael A. Phillips, +Mitchell Duke, +Stuart Forman, and others in North America)!

One of the projects I had my lab students work on this past semester when we got clouded out was finding as many of the occultations, eclipses, and multiple shadow transits of Jupiter's Galilean moons. Starting at 2015-01-24 about 04:00 UT, get setup for a gorgeous 3-D display. Both the shadow of Io and Callisto can be seen on the Jovian disk starting around 04:30 UT. Europa's shadow joins the bunch for a triple shadow transit about 06:25 UT. The triple shadow transit lasts a bit under 30 minutes, then we're back down to two shadows for the next 70 minutes.  This one is well placed for observers in the U.S. and Mexico.
4
Stephen Rahn's profile photoMitchell Duke's profile photoMichael A. Phillips's profile photo
9 comments
 
+Mitchell Duke like 2 weeks till opposition? 
Add a comment...
People
Have him in circles
8,553 people
Amanda Cole's profile photo
wilfred Densingh A's profile photo
Manuel Valcarcel's profile photo
Frank Merchant's profile photo
Martijn Roelandse's profile photo
‫سعيد سهرابي‬‎'s profile photo
John Bubb's profile photo
Thiago Viana Camata's profile photo
Andreas Pcensored's profile photo
Work
Occupation
Faculty member in Department of Physics and Astronomy
Basic Information
Gender
Male
Story
Tagline
Amateur professional/professional amateur astronomer
Bragging rights
Faster than a speeding Kuiper Belt Object. More powerful than a nebulous zephyr. Able to shoot deep sky objects in a single photon.
Education
  • University of Pennsylvania
    Physics, 1988 - 1993
  • Florida State University
    Physics, 1993 - 1997
  • University of Southern California
    Physics, 2004 - 2010
Links